Preparation of U-Nb alloy from oxide precursors by direct oxide electrochemical reduction method

Abstract

The aim of the present study was to prepare U-7 wt.% Nb alloy by the direct oxide electrochemical reduction method. The alloy was prepared from the mixed oxide precursors namely, UO2 and Nb2O5. When the precursors were sintered in a reducing atmosphere of Ar-8 vol.% H2, Nb2O5 was converted into NbO2. Subsequently, the mixed oxide pellet (UO2-NbO2) was reduced by the lithium metal, electrochemically generated from a molten LiCl-1 wt.% Li2O bath at 700°C. The electro-lithiothermic reduction was performed by constant current electrolysis mode with a mixed oxide pellet as the cathode and platinum as the anode. The reduction pathways of the individual oxides and the mixture were established using cyclic voltammetry and potentiostatic electrolysis techniques. The reduced alloy was characterized by X-ray diffraction and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS). These results confirmed the formation of U-Nb alloy. The composition of the alloy was determined by EDS, energy-dispersive X-ray fluorescence and chemical analysis.

Studies on Preparation of Thorium-Based Intermetallics in CaCl2 Melt by Electrochemical De-Oxidation Process

“…[16][17][18][19][20][21][22][23][24][25] Several important metals and alloys, including actinide metals and their alloys, e.g., U, Th, U-Pu, Pu-Fe, U-Ti, U-Mo, U-Nb alloys, etc, have been prepared using this method from their respective oxides. [26][27][28][29][30][31][32][33][34][35][36][37] Fray-Farthing-Chen (FFC) Cambridge process is one such process, wherein the reduction of metal oxide cathode is effected by electrons (electro-reduction), and the process is conventionally conducted in CaCl 2 melt at 900 °C. 38,39 A cell voltage less than the decomposition potential of CaCl 2 melt is applied between the metal oxide cathode and graphite anode.…”

“…Details about the design of the electrolysis cell are described elsewhere. 28,33 Assembly of the electrolysis cell with required electrodes and electrolyte (CaCl 2 ) was carried out inside the argon atmosphere glove box. Subsequently, the cell was taken out of the glove box and placed in a pit-type resistance furnace, wherein the electrochemical experiments were conducted at 900 °C under continuous purging of highpurity argon gas.…”

Electrochemical Preparation of ZrFe2 and ZrFe1.8Ni0.2 Intermetallic Compounds by FFC Cambridge Process

“…The preparation of Ni|NiO reference electrode and MCEs were reported elsewhere. 38 Sintered mixed oxide pellet tied with a tantalum wire (Alfa Aesar, purity 99.95%, metals basis, 0.5 mm dia.) was used as the cathode in electro-deoxidation experiments.…”